1. Field of the Invention
The present invention relates to multiple carburetion systems for automobile internal combustion engines, and more particularly to those in which two carburetors, each fed from a separate fuel source, alternately feed a fuel-air mixture into a single opening of a manifold.
2. Prior Art
The constantly rising cost of gasoline has made it desirable to employ alternate fuels to power automobiles having internal combustion engines. Alcohol provides a less expensive and renewable substitute for gasoline; however, alcohol fuel is not yet as readily available as gasoline. Therefore, the need exists for an automobile having an internal combustion engine with separate alcohol and gasoline fuel systems so that a driver may elect to power the automobile with gasoline should he run out of alcohol fuel and none is immediately available.
There are many devices known in the art which provide a means for supplying different types of fuel to an internal combustion engine through separate carburetors whose operation may occur simultaneously or alternately. For example, U.S. Pat. No. 2,023,634 discloses an internal combustion engine fitted with two independently fueled carburetors which can alternately feed through a shut off valve into a common conduit which feeds through a throttle valve into a manifold. Such a device is not practical for retrofitting since specially designed carburetors which do not have integral throttle valves are required. In addition, a separate throttling device must be installed between the conduit and the manifold.
U.S. Pat. No. 2,435,192 discloses a dual carburetor fuel system in which two carburetors are operated separately so that one carburetor is in operation for low engine speeds and the second carburetor becomes operable in addition to the first carburetor during high engine speeds. The throttle for each carburetor is separately linked to a mechanism connected to an accelerator pedal. A disadvantage of this device is that it requires the use of two independently operating manifolds which feed into two separate engine ports.
U.S. Pat. No. 2,444,665 discloses a system whereby two carburetors are used alternately to power an internal combustion engine with two separate fuels. The means for alternating carburetors comprises a control which alternately switches the fuel flow in a section of fuel line common to both fuel systems. The control is activated by pressing one of two foot pedals in the passenger compartment of the automobile. However, there are inherent disadvantages to this system; namely, two pedals are required, each with a separate linkage to a carburetor, and the necessity of a section of fuel line common to both fuel tanks results in a problem of contaminating one fuel with another thereby fouling the carburetors.
Other examples of dual carburetor systems which utilize two accelerator pedals, each linked with only one carburetor are disclosed in U.S. Pat. Nos. 2,446,034 and 2,075,330.
Accordingly, it is an object of the present invention to provide a dual fuel system utilizing two carburetors, each throttled by one accelerator pedal by means of one linkage controlling both carburetor throttles.
An additional object of the invention is to provide a dual fuel system utilizing two carburetors in which both carburetors feed an air fuel mixture into a single opening in a single common manifold.
A further object of the invention is to provide a dual fuel system which can utilize carburetors of standard design.